determine the relationship between the normal to the curve y=y = x^3-2 x at x=1 and x=-1
please show me how to do it
thankyou

October 2nd 2009, 04:02 PM

Matt Westwood

Quote:

Originally Posted by kayla220220

determine the relationship between the normal to the curve y=y = x^3-2 x at x=1 and x=-1
please show me how to do it
thankyou

The normal to a curve is by definition perpendicular to the tangent. So get the slope of the tangent of the curve in question by differentiating and plugging in the value x = 1. Then the perpendicular to a line of slope m has a slope (you will find this explained in your textbook somewhere).

So, the normal to the curve at that point is the straight line of the slope you've just calculated that passes through the point given. Then I suppose you would look at that line and compare it with the line x = -1.